Outrunning T. Rex

Q:Imagine a time-warp Kentucky Derby where somehow a 12,000-pound bi-pedal Tyrannosaurus rex chases a 1,000-pound modern racehorse. Could the thoroughbred run away?­E. Arcaro

A: Horses are good middle-distance runners, with legs and body structure suited for speed and stamina, says Miami University interdisciplinary studies professor Nancy Nicholson. Probably the rocking fore and aft of a galloping horse helps pump air in (rock back) and out (rock forward), piston-like.

Computer modelings suggest T. rex was no slouch either, with amazingly complex motions during a stride, and feet possibly best for straight line runs or gentle curves.

Moment of suspension is a fascinating factor, where for a galloping horse all four feet come off the ground simultaneously– a moment of friction-free airglide. "It makes no sense to assign such a moment to a beast the size of an adult T. rex, because of the huge forces in falling even a few inches."

So give the horse a credit on this one, and debit the dino on its ecological role as cleanup crew on large kills by other species, which does not argue for blazing speed.

Put it all together, concludes Nicholson, and a racing horse may do 40 mph, the dino did a highly speculative 10-25 mph. "So, for a mile and a quarter on a curved track, I vote for the horse by a factor of 2, with terror likely inducing an inspired performance on the part of the horse. On a straight track for that distance, I would think the difference would be less, but still vote for the horse to win the Triple Crown."

Q:One thrill of parenting is knowing you're passing along your genes to future generations. OK, Moms and Dads, since 50 percent of your genes– on average– go forth in each child, how many kids do you need to have to assure passing on your full gene "slate," albeit in bits and pieces?­M. Hubbard

A: Careful now. You can't just add 50 percent and 50 percent and assume two kids will do it. Problem here is your second kid's 50 percent of your genes overlaps half of your first kid's 50. So it's only 50 percent + 25 percent of you at this point, + 12.5 + 6 + 3 etc. for subsequent kids. So even after five kids there's still 3 percent of you "unexpressed," which just might be those beautiful eyes of yours or that gift for poetry.

How about 10 kids? Assuming 60,000 human genes, and other simplifications, by the time you get to your 10th kid you can expect to miss about 60 of your genes, on average, says Oxford University genetics statistician Carsten Wiuf. Make that 16 kids, and it's less than a single missed gene.

Still, that solo gene (or more) could slip through. To be rock-solid certain everything gets passed on, you'd need an infinity of kids. "In practice, 16 or so will do."

For a less exhausting approach, rely on your sibs and other family members to pass parts of you along.

Q:With only a handful of thumb tacks and a box of matches, devise a way to mount a short inch-thick candle on a bulletin board. Hint: Beware boxed-in thinking.­J. B. Nimble

A: Solving this requires realizing that a box need not always serve as a container, says David G. Myers in "Psychology." Just empty the matchbox, tack it up on the board, and drip-stick the candle onto a horizontal surface.

Another classic: Try to connect nine dots in a 3-by-3 array, using four straight lines and no re-tracings or picking up your pencil. Can't do it until you see to go outside the "box," then it's easy.

Rather more fanciful flex-thinking let 60s celluloid hero James Bond, armed with only a ballpoint pen filled with poisonous ink, escape a small island surrounded by alligators, in the movie Live and Let Die, says Erick Lauber on his "Cognitive Psychology Tutor" Web site. "With death imminent, Bond notices that five alligators have lined themselves in a row stretching from the island to the mainland. Rather than try to outswim the beasts or kill them with his pen, he runs to the safety of the shore by stepping on the tops of the alligators' heads."